1323a: 14-16: To seek out what is the best system of government, it is first necessary to define what is the most desirable life.

1323b: 1-4: Living happily, whether for human beings it comes from enjoyment or from excellence or from both, exists for those persons excessively adorned with character and purpose but moderate in the acquisition of external goods.

1295a: 25-1295b: Like the best life, the best system of government is conducted in accordance with excellence. If excellence is the mean, as argued in the Nicomachean Ethics [for example, at 1101a: 14-16], then a life and a system of government that is “in the middle” is best. A city-state has three elements in its population: the rich, the poor, and those in the middle. The political partnership that is constituted from those in the middle is the best.

1293a: 35-42: In addition to the four systems of government that [other] people usually bring up in discussing systems of government (namely, monarchy, oligarchy, democracy, and aristocracy), there is a fifth one called polity (politeia), which is also the term used to mean “system of government” in general or in a generic sense. This fifth system of government is sometimes overlooked in discussions of the types of systems of government since it does not come into existence very often.

1289a: 26-28: As was established previously in the first book of the Politics, there are three “straight” or “upright” [and therefore correct and good] systems of government (orthaipoliteiai): kingship, aristocracy, and polity.

1265b: 26-28: The system of government called polity is midway between democracy and oligarchy.

1293b: 33-37: Polity is, to put it simply, a mixture of oligarchy and democracy. The kinds of polities that tend towards democracy are customarily referred to by the name of polity, while those that tend towards oligarchy are called aristocracies.

1307a: 15-16: The systems of government inclining more toward oligarchy are called aristocracies, while those inclining more toward the multitude (plethos) [which can also mean “democracy”] are called polities.

1297b: 22-25: As city-states increased in size and grew stronger in the heavy-infantry [hoplite] section of the citizen body, more men gained a share in the system of government. For this reason what are now called polities were previously called democracies.

1279a: 37-39: When the multitude governs according to the common advantage, then this system of government is called by the term also used to designate systems of government in general, namely, polity.

1288a: 12-15: The multitude suitable for a polity is one capable of military service that has the natural ability to rule and be ruled in accordance with law that distributes offices to wealthier citizens on the basis of merit.

1307a: 5-8: Polities and aristocracies are undone by diverging from that which constitutes justice in the two different systems of government, [which is not necessarily the same thing in each system]. The starting point in a polity is when democracy and oligarchy have been not mixed appropriately [literally, “finely”].

1275b: 1-3: Diverging and erroneous systems of government are necessarily subsequent, not prior to correct [straight] systems.

1279b: 4-10: There are three systems of government diverging from the three “straight” systems: tyranny diverging from kingship, oligarchy diverging from aristocracy, and democracy diverging from polity. Each diverging system (parekbasis) is structured to operate to the advantage of the ruler(s); for example, democracy is rule to the advantage of the poor. None of the diverging systems aims at the profit of every type of citizen in common.

1289a: 28-1289b5: Of these three diverging systems of government, tyranny is the worst (which is to say the furthest from polity), oligarchy the next worst, and democracy the most moderate.

1279a: 17-21: While straight systems of government are concerned with the common advantage according to what is quite simply just, diverging forms of government are those that in error serve the interest of the ruler(s). Diverging forms of government tend to have an element of despotism, because a city-state is a partnership of the free.

1290a: 13-29: Some people claim that, just as there are two main kinds of wind or of musical harmonies, and the other winds and harmonies are regarded as divergences from these, there are also two sorts of systems of government, rule by the people and oligarchy. On this view, the, polity diverges from democracy and aristocracy diverges from oligarchy. But it is better to postulate instead that there are “straight” systems of government and systems of government diverging from them.

1259a: 39-1259b10: The rule that a husband has over his wife, a free person, is the same sort of rule that exists over free persons in a polity. Since the male is more fit to rule by nature, he will rule continuously in the household, unless he is somehow unnatural. In contrast, when citizens are equals and do not differ, then the roles of ruler and ruled will alternate.

1325b: 7-8: For those who are alike, the fine and the just is [to rule and be ruled] in turn, for this is equal and alike.

1282b: 10-13: Since laws align with the system of government, the laws of straight systems of government are necessarily just, but those of diverging systems are necessarily not just.

1309a: 36-39: Justice and the excellence associated with it are not the same in different systems of government.

1309b: 19-35: Diverging types of government fail to pay attention to the middle. Institutions suitable to a certain type of government can be the downfall of that type of government if they become too extreme. Just as a nose [on a statue] can still be appealing to look at if it diverges from the straightness that is beautiful but can become not even a nose if an artist pushes it too far in the direction of the extremes, so, too, a system of government such as democracy that diverges from the best system can still be adequate if it is not pushed to an extreme.

1287b: 39-41: There is no such thing as a person being naturally fitted for any of the diverging systems of governments, for they have come into being contrary to nature (physis).